1. Field of the Invention
Embodiments of the present invention generally relate to a wiper for a cosmetic container. The wiper allows for wiping excess product from an applicator upon removal from the container. More particularly, it relates to an elastomeric wiper which can be easily inserted into neck of the cosmetic container, and has novel locking features by which it can be retained in the neck of the container.
The wiper of the present invention can be particularly advantageous for use in the field of cosmetics, especially fluid cosmetic products such as mascaras, foundation, liquid rouge, eyeliners, eye shadow, lip tint, and lip gloss, but can also be used in other fields where wiping of the applicator is desirable.
2. Description of the Related Art
Typical applicator units for cosmetics such as mascara comprise a cosmetic container, a cosmetic contained in the cosmetic container, an applicator comprising a stem and an applicator head capable of being inserted in the cosmetic container in order to take the cosmetic, and a wiper comprising an elongated passage through which the applicator head passes longitudinally on being withdrawn from the container. The wiper is supported by a neck of the container. The wiper serves firstly to wipe the stem and secondly to remove excess cosmetic from the applicator head.
In certain cases such as where cross section of the applicator head varies along its length or the applicator head has small cross section relative to the stem, it is useful to employ a flexible wiper made up of an elastically deformable material.
Customarily, a flexible wiper is mounted in the neck of the cosmetic container to engage the applicator head as the applicator is withdrawn from the container. The wiper is advantageously a unitary body molded of a suitable elastomer, with an outer diameter dimensioned for a snug fit within the container neck, and may be assembled with the container by insertion into the neck. This flexible wiper removes excess product from the applicator head and/or the stem allowing the excess product to fall back or flow back into the container. Generally, this wiper is an open-ended tubular body which includes an elastic annular wiping lip, disposed in the container neck in surrounding relation to the path of the applicator through the neck. Such a wiper is shaped and dimensioned to engage the applicator snugly and conformingly as the applicator is withdrawn through the neck. At its upper end, the wiper includes an outwardly projecting annular sealing flange for overlying a rim of the neck.
Whenever the applicator head passes through a conventional wiper of the type just described, its engagement with the wiping lip exerts a force on the wiper, tending to move the wiper (relative to the container neck) in the direction in which the applicator is moving. If the applicator is being inserted into the container, the positive engagement of the upper sealing flange of the wiper with the rim of the neck prevents the wiper from being dislodged and pushed into the container. During withdrawal of the applicator, however, the sealing flange-rim engagement cannot act to hold the wiper in place, and owing to the inherent deformability of the elastomeric wiper, even interference fit between the wiper and the neck may not prevent the wiper from being pulled out of the container along with the applicator. Such accidental removal of the wiper is messy and inconvenient for the user.
In recent years several modifications have been done to overcome above-mentioned limitation. For Example, U.S. Pat. No. 4,617,948 discloses a wiper made of an elastically deformable material configured to be placed on an internal edge of the container, and held in place by an additional part forming a threaded neck. Such an arrangement, by entailing that the container be made in two parts, increases the number of assembly operations and raises the manufacturing cost of the unit.
In various prior arts, in order to retain the wiper in the container, it has been proposed to provide a solid bulge at the lower end of the wiper, the solid bulge configured to secure the wiper to the container. The bulge is configured to position itself behind the shoulder of the container, thus immobilizing the wiper in a position such that the wiper is secured to the container. Generally, the bulge has sufficient radial width to secure the wiper firmly to the container. For example, U.S. Pat. No. 7,476,044 discloses a wiper which includes an annular shoulder/a bulge arranged at its lower end to snap under the neck of the cosmetic container. The annular shoulder makes it difficult to insert the wiper into neck of the container.
Similar wipers with one or more relatively “solid” bulges are also described in U.S. Pat. No. 5,884,634 and U.S. Pat. No. 5,875,791. Such a system presents a drawback because the bulge renders the insertion of the wiper into the neck of the container difficult due to high resistance generated by the bulge.
U.S. Pat. No. 7,186,044 discloses an outwardly projecting, flexible annular flange or lip adjacent the lower end of the wiper, so as to underlie the interior of the container at the shoulder formed at the lower extremity of the neck. This flexible retaining flange folds or deforms upwardly as the wiper is forced into the neck during assembly and flexes in opposite direction upon emerging into the interior of the container below the neck when the wiper has been fully inserted. Thereafter the retaining flange is supposed to prevent outward movement of the wiper (relative to the neck) by engaging the container around the neck shoulder. The retaining flange is configured to flex axially in two opposing directions and when the wiper is mounted on the container, the flexible flange is elastically stressed which reduces structural strength of the flange.
EP0659366 discloses a tubular elastomeric wiper disposed in the container neck. In assembled condition, there is provided a cylindrical retaining sleeve which surrounds the wiper and has an interference-fit with wiper to retain the wiper in the container neck. The outer diameter of the sleeve is selected to provide a snug fit within the neck. The employment of retaining sleeve around wiper increases the number of components in the assembly and raises the manufacturing cost of the unit.
It would therefore be desirable to provide a wiper for a cosmetic container, of the general type described above, that mitigates or overcomes the aforementioned problems.